1. Technical Field:
This invention relates to devices for insufflating gas into a mass of molten metal and apparatus associated therewith enabling the condition of the devices to be determined at a remotely located indicator.
2. Description of the Prior Art:
Prior structures of this type have generally employed permeable plugs through which the gas is introduced into the liquid. Such typical devices may be seen in U.S. Pat. Nos. 2,811,346, 2,947,527, 3,330,645, 3,610,602 and 3,343,829. None of the devices of the prior art provide any apparatus usable in a method of determining the condition of the stirring block or the plugs associated therewith through which the gas is introduced into the ladle.
The present invention introduces heat sensors into the body of the stirring block and into the body of the plug used therein to define the gas passageway into the ladle and connects the heat sensors to appropriate indicating apparatus whereby temperatures in the block and the plug rising above a predetermined normal level serve to indicate the condition of the block and plug. Alternately Hall Effect transducers may be advantageously employed for the same purpose.